Pre-paid cellphone users in Vietnam will have to register with service providers from September, the Ministry of Posts and Telematics (MPT) has announced. Deputy Minister Le Nam Thang told a press briefing that all subscribers would have to provide their name together with some form of ID, but promised that the registration formalities would be simple and the information confidential. Existing users will be given two years to register, after which their service will be cut if they have not complied. The new rule is designed to protect users from prank calls and other forms of harassment, and also help authorities foil high-tech criminals who use mobile handsets to pass on information. One unnamed cellco official said it could, however also discourage subscribers from using the service and cause revenues to drop.